Title: Patterns of Marijuana Use for HIV/AIDS Pain Management: A Mixed Methods Approach Project Summary/Abstract This Kirschstein NRSA Predoctoral Fellowship proposal aims to conduct a cross sectional study assessing patters of marijuana use and pain among persons living with HIV (PLWH). This proposal responds to the National HIV/AIDS Strategy for the United States for improving health outcomes for people living with HIV. Additionally, this proposal will address NIDA?s goal of identifying biological, environmental, behavioral, and social causes and consequences of drug use across the lifespan. PLWH have a higher prevalence of severe pain compared to uninfected populations. Identifying predictors and alternative pain management options have become a top concern in the field. Currently literature targeting patterns of marijuana use and pain among PLWH has been limited to clinical control trials. Therefore, little is understood about how PLWH are currently using marijuana to manage pain. Cross-sectional data from 936 participants of the Florida Cohort HIV Study will be used to assess the relationship between patterns of marijuana use and pain severity among PLWH. To achieve this, the first aim is to identify biological, social, psychological, and substance use predictors of pain severity among PLWH. Biological, social, psychological, and substance use predictors will be selected using the biopsychosocial model. A multinomial logistic regression will be conducted to identify the strongest predictors of severe pain. The second aim is to assess predictors of cannabis use disorder among PLWH reporting pain. Predictors of cannabis use disorder will be assessed in accordance with the DSM-5 criteria. Severe pain will be calculated using a novel index. The third aim is to conduct thematic open-ended interviews targeting marijuana use for severe pain in PLWH. These interviews will specifically target perceived severity, susceptibility, benefits, and barriers of using marijuana to treat pain. The results of this study will have a public health impact on the identification of predictors of severe pain among PLWH, and the patterns of marijuana use among PLWH reporting severe pain. The training goals will specifically focus on developing stronger measures targeting severe pain, clinical trial training, presentation of findings, and manuscript production. The training goals will focus on 1) gaining clinical trial experience in measuring pain, 2) enhancing conceptual and practical understanding of how marijuana affects pain in PLWH, and 3) developing professional development skills, including first authored manuscript production, scientific presentations, and grant writing.